Close loop listen before talk for nr operation in unlicensed spectrum

ABSTRACT

Various embodiments disclosed herein provide for a closed loop Listen Before Talk (LBT) which is a coexistence mechanism used by wireless technologies such as Wi-Fi, to access unlicensed shared spectrum, such as the ISM UNII bands (5 GHz). The embodiments disclosed herein enable a base station to coordinate the LBT process at both the base station and a receiver in order to avoid hidden node interference where the interfering nodes are outside the sensing range of the transmitting node. The base station device can send a LBT trigger to the receiver to synchronize the clear channel assessments that are performed at each device to determine if there is any activity on the channel. The receiving device can send back a report to the base station device, and if no activity on the channel is detected, the base station device can schedule a transmission on the channel.

RELATED APPLICATIONS

The subject patent application is a continuation of, and claims priorityto each of, U.S. patent application Ser. No. 16/807,257, filed Mar. 3,2020, and entitled “CLOSE LOOP LISTEN BEFORE TALK FOR NR OPERATION INUNLICENSED SPECTRUM,” which is a continuation of U.S. patent applicationSer. No. 15/932,316 (now U.S. Pat. No. 10,624,126), filed Feb. 16, 2018,and entitled “CLOSE LOOP LISTEN BEFORE TALK FOR NR OPERATION INUNLICENSED SPECTRUM,” the entireties of which applications are herebyincorporated by reference herein.

TECHNICAL FIELD

The present application relates generally to the field of mobilecommunication and, more specifically, to implementing close loop ListenBefore Talk (LBT), a radio frequency coexistence mechanism for awireless communications transmission in a next generation wirelesscommunications network.

BACKGROUND

To meet the huge demand for data centric applications, Third GenerationPartnership Project (3GPP) systems and systems that employ one or moreaspects of the specifications of the Fourth Generation (4G) standard forwireless communications will be extended to a Fifth Generation (5G)standard for wireless communications. Unique challenges exist to providelevels of service associated with forthcoming 5G and other nextgeneration network standards.

BRIEF DESCRIPTION OF THE DRAWINGS

Non-limiting and non-exhaustive embodiments of the subject disclosureare described with reference to the following figures, wherein likereference numerals refer to like parts throughout the various viewsunless otherwise specified.

FIG. 1 illustrates an example wireless communication system inaccordance with various aspects and embodiments of the subjectdisclosure.

FIG. 2 illustrates an example block diagram showing a closed loop listenbefore talk system in accordance with various aspects and embodiments ofthe subject disclosure.

FIG. 3 illustrates an example block diagram showing a multi-user closedloop listen before talk system in accordance with various aspects andembodiments of the subject disclosure.

FIG. 4 illustrates an example block diagram showing a multi-cell closedloop listen before talk system in accordance with various aspects andembodiments of the subject disclosure.

FIG. 5 illustrates an example block diagram of a dual connectivityclosed loop listen before talk system in accordance with various aspectsand embodiments of the subject disclosure.

FIG. 6 illustrates an example block diagram of a base station deviceconfigured to perform closed loop listen before talk in accordance withvarious aspects and embodiments of the subject disclosure.

FIG. 7 illustrates an example method for performing closed loop listenbefore talk in accordance with various aspects and embodiments of thesubject disclosure.

FIG. 8 illustrates an example method for performing closed loop listenbefore talk in accordance with various aspects and embodiments of thesubject disclosure.

FIG. 9 illustrates an example block diagram of an example user equipmentthat can be a mobile handset operable to provide a format indicator inaccordance with various aspects and embodiments of the subjectdisclosure.

FIG. 10 illustrates an example block diagram of a computer that can beoperable to execute processes and methods in accordance with variousaspects and embodiments of the subject disclosure.

DETAILED DESCRIPTION

One or more embodiments are now described with reference to thedrawings, wherein like reference numerals are used to refer to likeelements throughout. In the following description, for purposes ofexplanation, numerous specific details are set forth in order to providea thorough understanding of the various embodiments. It is evident,however, that the various embodiments can be practiced without thesespecific details (and without applying to any particular networkedenvironment or standard).

Various embodiments disclosed herein provide for a closed loop ListenBefore Talk (LBT) which is a coexistence mechanism used by wirelesstechnologies such as Wi-Fi, to access unlicensed shared spectrum, suchas the ISM UNII bands (5 GHz). The embodiments disclosed herein enable abase station to coordinate the LBT process at both the base station anda receiver in order to avoid hidden node interference where theinterfering nodes are outside the sensing range of the transmittingnode. The base station device can send a LBT trigger to the receiver tosynchronize the clear channel assessments that are performed at eachdevice to determine if there is any activity on the channel. Thereceiving device can then send back a report to the base station device,and if both devices detect no activity on the channel, the base stationdevice can schedule a transmission on the channel.

While reference is generally made throughout the disclosure to adownlink communication, in other embodiments, the principles disclosedherein can apply to uplink transmissions as well. In both cases however,the base station device can initiate the LBT trigger in order tosynchronize and otherwise align the clear channel assessments performedat the mobile device and the base station device.

While reference is generally made throughout the disclosure to alignmentof LBT at the transmit node(s) and receive node(s), the principledisclosed herein applies to performing LBT on transmit node(s) only,receive node(s) only, or a subset of transmit and receive node(s).

Also the LBT used by New Radio (NR) (e.g., 5G) on unlicensed carriersshould have features and functionality that allow it to maximize thefrequency reuse especially when operating under light load or sparsedeployment. When the load is low or the deployment is sparse thelikelihood of collisions is low. Therefore, the LBT mechanism of NRunlicensed may adapt to such conditions and be utilized when needed. Forexample, the network on the licensed carrier may semi-statically (e.g.via radio resource control message) or dynamically (e.g. via downlinkcontrol information) determine whether or not to perform LBT at thetransmit node(s), receiving node(s), or both.

In various embodiments, a base station device can comprise a processorand a memory that stores executable instructions that, when executed bythe processor facilitate performance of operations. The operations cancomprise facilitating transmitting a first listen before talk trigger toa first mobile device via a downlink control channel, the first listenbefore talk trigger comprising an instruction to the first mobile deviceto perform a first clear channel assessment of a channel at a definedtime. The operations can also comprise performing a second clear channelassessment of the channel at the defined time. The operations can alsocomprise receiving a first result of the first clear channel assessmentfrom the first mobile device via an uplink control channel Theoperations can also comprise in response to the first result of thefirst clear channel assessment and a second result of the second clearchannel assessment indicating that the channel is clear, scheduling afirst transmission to the first mobile device via the channel.

In another embodiment, method comprises facilitating, by a base stationdevice comprising a processor, transmitting a request for a first clearchannel assessment to a first user equipment device via a downlinkcontrol channel, the request comprising an instruction to the first userequipment device to perform the first clear channel assessment on afrequency band at a predetermined time. The method can also compriseperforming, by the base station device, a second clear channelassessment on the frequency band at the predetermined time. The methodcan also comprise performing, by the base station device, a second clearchannel assessment on the frequency band at the predetermined time. Themethod can also comprise in response to the first result of the firstclear channel assessment and a second result of the second clear channelassessment indicating that the frequency band is clear, scheduling, bythe base station device, a first transmission to the first userequipment device on the frequency band.

In another embodiment machine-readable storage medium, comprisingexecutable instructions that, when executed by a processor of a device,facilitate performance of operations. The operations can comprisetransmitting a first listen before talk trigger to a first mobile devicevia a downlink control channel, the first listen before talk triggercomprising an instruction to the first mobile device to perform a firstclear channel assessment of a channel at a defined time. The operationscan also comprise performing a second clear channel assessment of thechannel at the defined time. The operations can also comprise receivinga result of the first clear channel assessment from the first mobiledevice via an uplink control channel The operations can also comprise inresponse to the first clear channel assessment and the second clearchannel assessment having determined that the channel is clear,scheduling a first transmission to the first mobile device via thechannel

As used in this disclosure, in some embodiments, the terms “component,”“system” and the like are intended to refer to, or comprise, acomputer-related entity or an entity related to an operational apparatuswith one or more specific functionalities, wherein the entity can beeither hardware, a combination of hardware and software, software, orsoftware in execution. As an example, a component may be, but is notlimited to being, a process running on a processor, a processor, anobject, an executable, a thread of execution, computer-executableinstructions, a program, and/or a computer. By way of illustration andnot limitation, both an application running on a server and the servercan be a component.

One or more components may reside within a process and/or thread ofexecution and a component may be localized on one computer and/ordistributed between two or more computers. In addition, these componentscan execute from various computer readable media having various datastructures stored thereon. The components may communicate via localand/or remote processes such as in accordance with a signal having oneor more data packets (e.g., data from one component interacting withanother component in a local system, distributed system, and/or across anetwork such as the Internet with other systems via the signal). Asanother example, a component can be an apparatus with specificfunctionality provided by mechanical parts operated by electric orelectronic circuitry, which is operated by a software application orfirmware application executed by a processor, wherein the processor canbe internal or external to the apparatus and executes at least a part ofthe software or firmware application. As yet another example, acomponent can be an apparatus that provides specific functionalitythrough electronic components without mechanical parts, the electroniccomponents can comprise a processor therein to execute software orfirmware that confers at least in part the functionality of theelectronic components. While various components have been illustrated asseparate components, it will be appreciated that multiple components canbe implemented as a single component, or a single component can beimplemented as multiple components, without departing from exampleembodiments.

Further, the various embodiments can be implemented as a method,apparatus or article of manufacture using standard programming and/orengineering techniques to produce software, firmware, hardware or anycombination thereof to control a computer to implement the disclosedsubject matter. The term “article of manufacture” as used herein isintended to encompass a computer program accessible from anycomputer-readable (or machine-readable) device or computer-readable (ormachine-readable) storage/communications media. For example, computerreadable storage media can comprise, but are not limited to, magneticstorage devices (e.g., hard disk, floppy disk, magnetic strips), opticaldisks (e.g., compact disk (CD), digital versatile disk (DVD)), smartcards, and flash memory devices (e.g., card, stick, key drive). Ofcourse, those skilled in the art will recognize many modifications canbe made to this configuration without departing from the scope or spiritof the various embodiments.

In addition, the words “example” and “exemplary” are used herein to meanserving as an instance or illustration. Any embodiment or designdescribed herein as “example” or “exemplary” is not necessarily to beconstrued as preferred or advantageous over other embodiments ordesigns. Rather, use of the word example or exemplary is intended topresent concepts in a concrete fashion. As used in this application, theterm “or” is intended to mean an inclusive “or” rather than an exclusive“or”. That is, unless specified otherwise or clear from context, “Xemploys A or B” is intended to mean any of the natural inclusivepermutations. That is, if X employs A; X employs B; or X employs both Aand B, then “X employs A or B” is satisfied under any of the foregoinginstances. In addition, the articles “a” and “an” as used in thisapplication and the appended claims should generally be construed tomean “one or more” unless specified otherwise or clear from context tobe directed to a singular form.

Moreover, terms such as “mobile device equipment,” “mobile station,”“mobile,” subscriber station,” “access terminal,” “terminal,” “handset,”“communication device,” “mobile device” (and/or terms representingsimilar terminology) can refer to a wireless device utilized by asubscriber or mobile device of a wireless communication service toreceive or convey data, control, voice, video, sound, gaming orsubstantially any data-stream or signaling-stream. The foregoing termsare utilized interchangeably herein and with reference to the relateddrawings. Likewise, the terms “access point (AP),” “Base Station (BS),”BS transceiver, BS device, cell site, cell site device, “Node B (NB),”“evolved Node B (eNode B),” “home Node B (HNB)” and the like, areutilized interchangeably in the application, and refer to a wirelessnetwork component or appliance that transmits and/or receives data,control, voice, video, sound, gaming or substantially any data-stream orsignaling-stream from one or more subscriber stations. Data andsignaling streams can be packetized or frame-based flows.

Furthermore, the terms “device,” “communication device,” “mobiledevice,” “subscriber,” “customer entity,” “consumer,” “customer entity,”“entity” and the like are employed interchangeably throughout, unlesscontext warrants particular distinctions among the terms. It should beappreciated that such terms can refer to human entities or automatedcomponents supported through artificial intelligence (e.g., a capacityto make inference based on complex mathematical formalisms), which canprovide simulated vision, sound recognition and so forth.

Embodiments described herein can be exploited in substantially anywireless communication technology, comprising, but not limited to,wireless fidelity (Wi-Fi), global system for mobile communications(GSM), universal mobile telecommunications system (UMTS), worldwideinteroperability for microwave access (WiMAX), enhanced general packetradio service (enhanced GPRS), third generation partnership project(3GPP) long term evolution (LTE), third generation partnership project 2(3GPP2) ultra mobile broadband (UMB), high speed packet access (HSPA),Z-Wave, Zigbee and other 802.XX wireless technologies and/or legacytelecommunication technologies.

FIG. 1 illustrates an example wireless communication system 100 inaccordance with various aspects and embodiments of the subjectdisclosure. In one or more embodiments, system 100 can comprise one ormore user equipment UEs 104 and 102, which can have one or more antennapanels having vertical and horizontal elements. A UE 102 can be a mobiledevice such as a cellular phone, a smartphone, a tablet computer, awearable device, a virtual reality (VR) device, a heads-up display (HUD)device, a smart car, a machine-type communication (MTC) device, and thelike. UE 102 can also refer to any type of wireless device thatcommunicates with a radio network node in a cellular or mobilecommunication system. Examples of UE 102 are target device, device todevice (D2D) UE, machine type UE or UE capable of machine to machine(M2M) communication, PDA, Tablet, mobile terminals, smart phone, laptopembedded equipped (LEE), laptop mounted equipment (LME), USB donglesetc. User equipment UE 102 can also comprise IOT devices thatcommunicate wirelessly. In various embodiments, system 100 is orcomprises a wireless communication network serviced by one or morewireless communication network providers. In example embodiments, a UE102 can be communicatively coupled to the wireless communication networkvia a network node 106.

The non-limiting term network node (or radio network node) is usedherein to refer to any type of network node serving a UE 102 and UE 104and/or connected to other network node, network element, or anothernetwork node from which the UE 102 or 104 can receive a radio signal.Network nodes can also have multiple antennas for performing varioustransmission operations (e.g., MIMO operations). A network node can havea cabinet and other protected enclosures, an antenna mast, and actualantennas. Network nodes can serve several cells, also called sectors,depending on the configuration and type of antenna. Examples of networknodes (e.g., network node 106) can comprise but are not limited to:NodeB devices, base station (BS) devices, access point (AP) devices, andradio access network (RAN) devices. The network node 106 can alsocomprise multi-standard radio (MSR) radio node devices, including butnot limited to: an MSR BS, an eNode B, a network controller, a radionetwork controller (RNC), a base station controller (BSC), a relay, adonor node controlling relay, a base transceiver station (BTS), atransmission point, a transmission node, an RRU, an RRH, nodes indistributed antenna system (DAS), and the like. In 5G terminology, thenode 106 can be referred to as a gNodeB device.

Wireless communication system 100 can employ various cellulartechnologies and modulation schemes to facilitate wireless radiocommunications between devices (e.g., the UE 102 and 104 and the networknode 106). For example, system 100 can operate in accordance with aUMTS, long term evolution (LTE), high speed packet access (HSPA), codedivision multiple access (CDMA), time division multiple access (TDMA),frequency division multiple access (FDMA), multi-carrier code divisionmultiple access (MC-CDMA), single-carrier code division multiple access(SC-CDMA), single-carrier FDMA (SC-FDMA), OFDM, (DFT)-spread OFDM orSC-FDMA)), FBMC, ZT DFT-s-OFDM, GFDM, UFMC, UW DFT-Spread-OFDM, UW-OFDM,CP-OFDM, resource-block-filtered OFDM, and UFMC. However, variousfeatures and functionalities of system 100 are particularly describedwherein the devices (e.g., the UEs 102 and 104 and the network device106) of system 100 are configured to communicate wireless signals usingone or more multi carrier modulation schemes, wherein data symbols canbe transmitted simultaneously over multiple frequency subcarriers (e.g.,OFDM, CP-OFDM, DFT-spread OFMD, UFMC, FMBC, etc.).

In various embodiments, system 100 can be configured to provide andemploy 5G wireless networking features and functionalities. 5G wirelesscommunication networks are expected to fulfill the demand ofexponentially increasing data traffic and to allow people and machinesto enjoy gigabit data rates with virtually zero latency. Compared to 4G,5G supports more diverse traffic scenarios. For example, in addition tothe various types of data communication between conventional UEs (e.g.,phones, smartphones, tablets, PCs, televisions, Internet enabledtelevisions, etc.) supported by 4G networks, 5G networks can be employedto support data communication between smart cars in association withdriverless car environments, as well as machine type communications(MTCs).

In an embodiment, network node 106 or UE 102 and UE 104 can performclear channel assessments (CCA) on channels to avoid sending atransmission on a beam that already has activity on the channel. In anembodiment, the network node 106 can send a LBT trigger to the UE 104and/or the UE 102 in order to coordinate the LBT process which comprisesa clear channel assessment and then reporting the results of the clearchannel assessment back to the network node 106. If the network nodedetermines that there is no activity on the channel at both thetransmitter and receiver side, the network node 106 can schedule atransmission on the channel.

Listen Before Talk (LBT) is a coexistence mechanism used by wirelesstechnologies, such as Wi-Fi, to access unlicensed shared spectrum, suchas the ISM UNII (Unlicensed National Information Infrastructure) bands(5 GHz). A form of LBT is required by regulation in some countries andregions, such as Europe and Japan. In the US although LBT is notrequired by regulation, it is used by Wi-Fi and LTE License AssistedAccess (LAA) for coexistence purposes. In an embodiment, in LAA, thedata channel can use the unlicensed channel for improved throughput, butthe control signaling can be performed using the licensed carriers forimproved robustness and low latency since those resources are dedicatedfor the operator and not subject to coexistence requirements. Howeverthe data channel, on which the LBT is being performed can be anunlicensed carrier that is typically used for offloading datatransmissions from the licensed carriers due to the large availablebandwidth.

As part of the LBT procedure the devices perform spectrum sensing alsoknown as Clear Channel Assessment (CCA), where multiple time/frequencyslots are measured with respect to a configured energy detection (ED)threshold. While LBT performed independently at a transmitting node canbe used to avoid collisions of transmissions at a target receiver, theperformance may suffer from so-called “hidden node problems” if theinterfering transmitting nodes are outside the sensing range of thetransmitting node. Due to the challenges of hidden nodes and associatedlatency incurred by LBT procedures on unlicensed carriers, it isbeneficial to utilize the licensed (NR-L) and unlicensed (NR-U) carriersin LAA deployments jointly to perform LBT procedures. Variousembodiments herein disclose methods for utilizing the licensed carrierto provide LBT configuration, feedback, and coordination in networksutilizing LAA.

In one or more embodiments, NR (“New Radio” e.g., 5G) may operate in sub6 GHz or above 6 GHz spectrum, including licensed and unlicensedspectrum. Especially in higher frequency bands, the performance of LBTmay be improved significantly with transmit and receive beamforming. 5Gsystems, especially for mmWave spectrum, will have a large number ofantenna elements which could be used for analog, digital or hybridbeamforming. With Time Division Duplex (TDD) transmission, everytransmit beam has a corresponding receive beam with identicalcharacteristics. Using this property a transceiver can sense during LBTif other users are active on some beams but not on other beams. Thisallows the transceiver to use the inactive beams for its transmissions,thus increasing channel reuse efficiency without causing interference.

Closed loop LBT can be beneficial in combination with multi-beam LBT byaggregating the CCA results for multiple groups of Tx/Rx beam pairs fora given device. The LBT trigger may include an indication to performchannel sensing on one or more beam pair links (BPL) corresponding todifferent combinations of Tx/Rx beams. This can includequasi-co-location (QCL) information for each BPL associated with a givenset of LBT parameters. The QCL information may include indication thatfor a given BPL a set of RS/transmissions may be assumed by the UE to bequasi-co-located (e.g. identical geographically) with respect to Dopplerspread, Doppler shift, average gain, average delay, and spatial Rxparameters The LBT trigger may be independently sent for each BPL or maybe provided once for a set of BPLs.

Closed Loop LBT Feedback can also be sent from a UE corresponding to oneor more configured BPLs that the UE utilized when performing channelsensing. The network may determine which subset of BPLs to use for agiven UE based on whether LBT is successful and whether it can pairother UEs or multiple spatial layers. In this case synchronization ofLBT at the transmitter and receiver refers to the same time as well onthe same beam pair links. In one example the UE performs the LBT acrossmultiple BPLs independently and sequentially. In another example, if aUE is capable of supporting multiple BPLs the LBT feedback can also beused to enable transmissions from multiple transmission or receptionpoints (TRPs) in a given cell by synchronizing the LBT of multiple BPLsfrom different TRPs simultaneously. In one example the LBT triggers maybe sent via multiple DCIs for each TRP or may be sent by a common DCI.In another example the LBT feedback may be sent via multiple UL messagesor may be sent via common messages which group the BPLs or subsets ofBPLs.

Closed-loop LBT can be utilized in the case where multiple NR-U carriersor bandwidth parts (BWPs) are utilized. In this case the LBT trigger mayindicate a set of carriers/BWP for performing synchronized LBT eitherindependently or jointly. The trigger may also indicate a priority ortime pattern for performing LBT across the multiple carriers/BWPs incase the UE is not capable of performing simultaneous LBT across them.

In addition, the LBT feedback messages may include the carrier sensingstatus of multiple carriers in the same message or different feedbackmessages for each carrier. Closed-Loop LBT can be used in case ofcontiguous and non-contiguous operation of multiple carriers/BWPs

Turning now to FIG. 2, illustrated is an example block diagram 200showing a closed loop listen before talk system in accordance withvarious aspects and embodiments of the subject disclosure.

In an embodiment, a base station device 202 can send a LBT trigger 210to mobile device 204 in order to facilitate scheduling an uplink ordownlink transmission from or to the mobile device 204. The trigger cancoordinate the clear channel assessments (CCA) performed such that theyoccur at roughly the same time at both the mobile device 204 and thebase station device 202. If the CCA performed at the mobile device 204and the base station device 202 is clear (e.g., no activity on theunlicensed channel/frequency band is detected) then the mobile device204 can send back a report 216 to the base station device indicating theresults, and the base station device 202 can initiate scheduling of thetransmission. If on the other hand, the CCA performed at the mobiledevice 204 detects a transmission (e.g., transmission 214) from mobiledevice 208 that is part of a transmission 212 to base station device206, then the mobile device 204 can determine that there is activity onthe channel, and inform the base station device 202 about the activity.Base station device 202 can then wait a predetermined period of time orsend a second LBT trigger to see if there continues to be activity onthe channel at a later time.

In an embodiment, the LBT trigger can be sent on a downlink controlchannel (e.g., PDCCH or PDSCH), or on a new dedicated physical channel.The trigger can include a request to perform the clear channelassessment as well as providing parameters indicating how the mobiledevice 204 should perform the CCA. The indicated LBT parameters mayinclude a starting time location/offset for carrier sensing as well as aduration in symbols/slots, energy detection threshold, LBT type,priority, etc. Upon receiving the LBT trigger at the mobile device 204,the base station device 202 and mobile device 204 can performsynchronized LBT. The LBT trigger downlink channel information (DCI) mayor may not require an acknowledgement message from the UE. By utilizingthe licensed carrier associated with channels 210 and 216, the LBTprocedure can become more robust with lower latency/overhead thantechniques which can only utilized unlicensed spectrum.

After performing LBT the mobile device 204 can feedback the channelsensing status to the gNB which then can utilize the feedback todetermine whether the channel is clear at both ends of the link. The LBTfeedback is carried on the licensed carrier (NR-L) carrier in the formof an uplink control message, e.g. on PUCCH or PUSCH or on a newdedicated physical channel for indicating the result of the carriersensing. In addition the LBT feedback can be included or carried in a“piggyback” fashion on other control channel messages or feedback suchas HARQ ACK/NACK, CSI or beam management reports, UL data transmissions,or UL scheduling requests/buffer status reports.

The LBT feedback message may contain information such as clear channelassessment status on a per-symbol or per LBT duration. In one examplethe LBT feedback of the channel status for a LBT occasion on a givenlink can be indicated as a 1-bit message (e.g. clear/not clear). Inanother example the LBT feedback may include additional informationregarding the identities and/or measurements such as channel occupancyindication (time/frequency/spatial occupancy) and RSRP/RSSImeasurement(s) of detected potentially interfering transmitters.

In one example the LBT feedback is provided in the uplink portion of aself-contained subframe/slot, whether the LBT trigger is carried in thedownlink portion of the same subframe/slot. In another example the LBTtrigger and/or feedback may be carried on mini-slots within the durationof a slot. This is beneficial to reduce the delay between LBT triggerand feedback in case the LBT duration is short. In case of longer LBTdurations which are more than one slot in length, the LBT trigger DCImay indicate the timing of the LBT feedback message, for example thestarting slot or symbol offset. In another example the LBT feedbacktiming is implicitly determined based on the duration of the LBT sensingperiod.

LBT feedback may also be provided on the unlicensed channel. Thefeedback signal carries information about the intended transmittingnode. This allows collision avoidance by informing other nodes in thevicinity about the impending transmission

In addition, longer term feedback may be provided via higher layermessages on the licensed carrier for example by radio resource control(RRC) signaling. Closed-Loop LBT operation may be configured for a givenUE (e.g., mobile device 204) via dedicated (RRC) or broadcast signaling(e.g. system information broadcast) messages.

Turning now to FIG. 3, illustrated is an example block diagram 300showing a multi-user closed loop listen before talk system in accordancewith various aspects and embodiments of the subject disclosure.

In an embodiment, the base station device 304 can coordinate LBT betweenboth devices 306 and 308 by sending LBT triggers 310 and 314 to thedevices 306 and 308 respectively requesting CCAs to be performed at thesame time. Devices 306 and 308 can then send back their reports 312 and316 to the base station device 304 for the base station device 304 todetermine whether to facilitate scheduling a transmission to eitherdevice 306 or 308. If for example, device 308 detects activity on theunlicensed channel, but device 306 and base station device 304 do not,then the base station device 304 can schedule a transmission between thebase station device 304 and the mobile device 306, while sending asecond LBT trigger to device 308.

The closed loop LBT can be extended to multiple UEs allowing forsynchronized LBT across all of them. This is shown in FIG. 4. The gNB1sends LBT triggers to both UE1 and UE2 which aligns their clear channelassessment (CCA) periods. When both UEs complete the sensing they sendLBT feedback messages on the NR-L carrier providing the sensing result.This enables the gNB to determine which of the UEs should be scheduledbased on whether the channel is clear on both ends of the gNB/UE link.In case multiple UEs indicate clear channel status, the gNB may schedulethem simultaneously for example with multi-user MIMO transmissions,increasing the spectral efficiency of the NR-U carrier.

Multi-User Closed Loop LBT can be extended to support both downlink anduplink multi-user multiple input/multiple output (MU-MIMO), where theLBT trigger may be precede or be combined with a uplink datatransmission grant for UEs which detect a clear channel during LBT.

Turning now to FIG. 4, illustrated is an example block diagram 400showing a multi-cell closed loop listen before talk system in accordancewith various aspects and embodiments of the subject disclosure.

In an embodiment, a base station device 402 and a base station 406 cancoordinate the LBT process such each of the base stations 402 and 406and devices 408 and 404 are aligned when performing the CCA. The basestations 402 and 406 can communicate with each other over the air, orvia a backhaul network 424, and can respectively send LBT triggers 410and 418 to the mobile devices 404 and 408. Upon receiving back CCAreports 416 and 412 from devices 404 and 408, base station devices 402and 406 can determine whether to schedule transmission to either ofdevices 404 and/or 408.

Depending on whether any transmissions of other nodes were detected thebase stations 402 and 406 can independently decide which of mobiledevices 404 and 408 to schedule. However if the channel was detected tobe clear by mobile devices of different cells, Reuse-1 transmissions 420and 422 may be sent from the base station devices 402 and 406 to themobile devices 404 and 408 respectively and the downlink or uplinkgrants can be sent for the mobile devices 404 and 408 to transmitsimultaneously on the uplink. Since the Reuse-1 transmissions are fromnodes of the same operator the interference can be managed using CSImeasurements and reports and is expected to be significantly less of afactor than interference in the case of transmissions from nodes notpart of the same network. Coordination of LBT parameters between gNBsmay be done over the X2 interface.

Multi-cell coordination is useful when nearby cells are deployed by thesame operator and interfering transmissions from other sources (e.g.other operators) may be absent on a long term basis. In this case, theoverhead of LBT can be reduced or eliminated through spectrum reuse(e.g. reuse 1 420 and 422) for transmissions from the same operator,without requiring global coordination of transmissions via backhaulsignaling.

In FIG. 4, both base station device 402 and base station device 406 sendLBT triggers to their connected UEs, mobile device 404 and 408respectively, in order to align their CCA durations and LBT parameters.After the CCA, the mobile devices 404 and 408 provide feedback of theLBT status to the serving base stations via CCA reports 416 and 412.Depending on whether any transmissions of other nodes were detected thebase station devices 402 and 406 can independently decide which UEs toschedule. However if the channel was detected to be clear by UEs ofdifferent cells, Reuse-1 transmissions 420 and 422 may be sent from thebase station devices 402 and 406 to the mobile devices 404 and 408 inthe DL or UL grants can be sent for the mobile devices 404 and 408 totransmit simultaneously on the UL. Since the Reuse-1 transmissions 420and 422 are from nodes of the same operator the interference can bemanaged using CSI measurements and reports and is expected to besignificantly less of a factor than interference in the case oftransmissions from nodes not part of the same network.

Turning now to FIG. 5, illustrated is an example block diagram 500 of adual connectivity closed loop listen before talk system in accordancewith various aspects and embodiments of the subject disclosure.

NR can be deployed as a standalone (SA) radio access technology or as anon-standalone (NSA) radio access technology assisted by another radioaccess technology. In one example LTE can be used as a mobility anchorcomprising a master cell group (MCG) base station device 504, while NR-Uis used as a secondary cell group (e.g., base station device 502). TheClosed-Loop LBT triggers and feedback messages are carried on the MCGwhile the sensing and data transmissions are carried on the SCG NR-Ucarriers. The coordination of LBT parameters and status may be providedvia backhaul or over the air signaling (e.g., message 5012) between theLTE master node 504 and the NR-U secondary node 502 as shown in FIG. 5.The target transmission 508 can be sent to the mobile device 506 whenthen provides CCA/LBT feedback 510 to the master cell group base stationdevice 504.

Turning now to FIG. 6, illustrated is an example block diagram 600 of abase station device 602 configured to perform closed loop listen beforetalk in accordance with various aspects and embodiments of the subjectdisclosure.

Base station device 602 can include a trigger component 604 that canfacilitate issuing a first listen before talk trigger to a first mobiledevice via a downlink control channel, the first listen before talktrigger comprising an instruction to the first mobile device to performa first clear channel assessment of a channel at a defined time. Thetransceiver component 610 can transmit the trigger on a downlink controlchannel to the mobile device.

A CCA component 606 can then perform the CCA at the base station device602 at the same time as the base station device 602 requested the mobiledevice perform the CCA. The transceiver component 610 can then receive aresult of the mobile device's CCA report via an uplink control channelThe scheduling component 608 can then in response to the first result ofthe first clear channel assessment and a second result of the secondclear channel assessment indicating that the channel is clear, schedulea first transmission to the first mobile device via the channel

FIGS. 7-8 illustrates a process in connection with the aforementionedsystems. The processes in FIGS. 7-8 can be implemented for example bythe systems in FIGS. 1-6 respectively. While for purposes of simplicityof explanation, the methods are shown and described as a series ofblocks, it is to be understood and appreciated that the claimed subjectmatter is not limited by the order of the blocks, as some blocks mayoccur in different orders and/or concurrently with other blocks fromwhat is depicted and described herein. Moreover, not all illustratedblocks may be required to implement the methods described hereinafter.

FIG. 7 illustrates an example method 700 performing closed loop listenbefore talk in accordance with various aspects and embodiments of thesubject disclosure.

Method 700 can begin at 702 where the method includes facilitating, by abase station device comprising a processor, transmitting a request for afirst clear channel assessment to a first user equipment device via adownlink control channel, the request comprising an instruction to thefirst user equipment device to perform the first clear channelassessment on a frequency band at a predetermined time.

At 704, the method includes performing, by the base station device, asecond clear channel assessment on the frequency band at thepredetermined time.

At 706, the method includes facilitating, by the base station device,receiving a first result of the first clear channel assessment from thefirst user equipment device via an uplink control channel.

At 708, the method includes in response to the first result of the firstclear channel assessment and a second result of the second clear channelassessment indicating that the frequency band is clear, scheduling, bythe base station device, a first transmission to the first userequipment device on the frequency band.

FIG. 8 illustrates an example method 800 performing closed loop listenbefore talk in accordance with various aspects and embodiments of thesubject disclosure.

Method 800 can begin at 802 wherein the method includes facilitating, bythe base station device, transmitting a second request for a secondclear channel assessment to a second user equipment device, wherein thesecond clear channel assessment synchronizes a third clear channelassessment for the second user equipment device with a timing for thefirst clear channel assessment of the user equipment device.

At 804, the method can include scheduling, by the base station device, asecond transmission to the second user equipment device in response to athird result of the third clear channel assessment being clear and thefirst result of the first clear channel assessment being detection ofactivity on the frequency band.

Referring now to FIG. 9, illustrated is a schematic block diagram of anexample end-user device such as a user equipment) that can be a mobiledevice 900 capable of connecting to a network in accordance with someembodiments described herein. Although a mobile handset 900 isillustrated herein, it will be understood that other devices can be amobile device, and that the mobile handset 900 is merely illustrated toprovide context for the embodiments of the various embodiments describedherein. The following discussion is intended to provide a brief, generaldescription of an example of a suitable environment 900 in which thevarious embodiments can be implemented. While the description includes ageneral context of computer-executable instructions embodied on amachine-readable storage medium, those skilled in the art will recognizethat the various embodiments also can be implemented in combination withother program modules and/or as a combination of hardware and software.

Generally, applications (e.g., program modules) can include routines,programs, components, data structures, etc., that perform particulartasks or implement particular abstract data types. Moreover, thoseskilled in the art will appreciate that the methods described herein canbe practiced with other system configurations, includingsingle-processor or multiprocessor systems, minicomputers, mainframecomputers, as well as personal computers, hand-held computing devices,microprocessor-based or programmable consumer electronics, and the like,each of which can be operatively coupled to one or more associateddevices.

A computing device can typically include a variety of machine-readablemedia. Machine-readable media can be any available media that can beaccessed by the computer and includes both volatile and non-volatilemedia, removable and non-removable media. By way of example and notlimitation, computer-readable media can comprise computer storage mediaand communication media. Computer storage media can include volatileand/or non-volatile media, removable and/or non-removable mediaimplemented in any method or technology for storage of information, suchas computer-readable instructions, data structures, program modules orother data. Computer storage media can include, but is not limited to,RAM, ROM, EEPROM, flash memory or other memory technology, CD ROM,digital video disk (DVD) or other optical disk storage, magneticcassettes, magnetic tape, magnetic disk storage or other magneticstorage devices, or any other medium which can be used to store thedesired information and which can be accessed by the computer.

Communication media typically embodies computer-readable instructions,data structures, program modules or other data in a modulated datasignal such as a carrier wave or other transport mechanism, and includesany information delivery media. The term “modulated data signal” means asignal that has one or more of its characteristics set or changed insuch a manner as to encode information in the signal. By way of example,and not limitation, communication media includes wired media such as awired network or direct-wired connection, and wireless media such asacoustic, RF, infrared and other wireless media. Combinations of the anyof the above should also be included within the scope ofcomputer-readable media.

The handset 900 includes a processor 902 for controlling and processingall onboard operations and functions. A memory 904 interfaces to theprocessor 902 for storage of data and one or more applications 906(e.g., a video player software, user feedback component software, etc.).Other applications can include voice recognition of predetermined voicecommands that facilitate initiation of the user feedback signals. Theapplications 906 can be stored in the memory 904 and/or in a firmware908, and executed by the processor 902 from either or both the memory904 or/and the firmware 908. The firmware 908 can also store startupcode for execution in initializing the handset 900. A communicationscomponent 910 interfaces to the processor 902 to facilitatewired/wireless communication with external systems, e.g., cellularnetworks, VoIP networks, and so on. Here, the communications component910 can also include a suitable cellular transceiver 911 (e.g., a GSMtransceiver) and/or an unlicensed transceiver 913 (e.g., Wi-Fi, WiMax)for corresponding signal communications. The handset 900 can be a devicesuch as a cellular telephone, a PDA with mobile communicationscapabilities, and messaging-centric devices. The communicationscomponent 910 also facilitates communications reception from terrestrialradio networks (e.g., broadcast), digital satellite radio networks, andInternet-based radio services networks.

The handset 900 includes a display 912 for displaying text, images,video, telephony functions (e.g., a Caller ID function), setupfunctions, and for user input. For example, the display 912 can also bereferred to as a “screen” that can accommodate the presentation ofmultimedia content (e.g., music metadata, messages, wallpaper, graphics,etc.). The display 912 can also display videos and can facilitate thegeneration, editing and sharing of video quotes. A serial I/O interface914 is provided in communication with the processor 902 to facilitatewired and/or wireless serial communications (e.g., USB, and/or IEEE1394) through a hardwire connection, and other serial input devices(e.g., a keyboard, keypad, and mouse). This supports updating andtroubleshooting the handset 900, for example. Audio capabilities areprovided with an audio I/O component 916, which can include a speakerfor the output of audio signals related to, for example, indication thatthe user pressed the proper key or key combination to initiate the userfeedback signal. The audio I/O component 916 also facilitates the inputof audio signals through a microphone to record data and/or telephonyvoice data, and for inputting voice signals for telephone conversations.

The handset 900 can include a slot interface 918 for accommodating a SIC(Subscriber Identity Component) in the form factor of a card SubscriberIdentity Module (SIM) or universal SIM 920, and interfacing the SIM card920 with the processor 902. However, it is to be appreciated that theSIM card 920 can be manufactured into the handset 900, and updated bydownloading data and software.

The handset 900 can process IP data traffic through the communicationcomponent 910 to accommodate IP traffic from an IP network such as, forexample, the Internet, a corporate intranet, a home network, a personarea network, etc., through an ISP or broadband cable provider. Thus,VoIP traffic can be utilized by the handset 800 and IP-based multimediacontent can be received in either an encoded or decoded format.

A video processing component 922 (e.g., a camera) can be provided fordecoding encoded multimedia content. The video processing component 922can aid in facilitating the generation, editing and sharing of videoquotes. The handset 900 also includes a power source 924 in the form ofbatteries and/or an AC power subsystem, which power source 924 caninterface to an external power system or charging equipment (not shown)by a power I/O component 926.

The handset 900 can also include a video component 930 for processingvideo content received and, for recording and transmitting videocontent. For example, the video component 930 can facilitate thegeneration, editing and sharing of video quotes. A location trackingcomponent 932 facilitates geographically locating the handset 900. Asdescribed hereinabove, this can occur when the user initiates thefeedback signal automatically or manually. A user input component 934facilitates the user initiating the quality feedback signal. The userinput component 934 can also facilitate the generation, editing andsharing of video quotes. The user input component 934 can include suchconventional input device technologies such as a keypad, keyboard,mouse, stylus pen, and/or touch screen, for example.

Referring again to the applications 906, a hysteresis component 936facilitates the analysis and processing of hysteresis data, which isutilized to determine when to associate with the access point. Asoftware trigger component 938 can be provided that facilitatestriggering of the hysteresis component 938 when the Wi-Fi transceiver913 detects the beacon of the access point. A SIP client 940 enables thehandset 900 to support SIP protocols and register the subscriber withthe SIP registrar server. The applications 906 can also include a client942 that provides at least the capability of discovery, play and storeof multimedia content, for example, music.

The handset 900, as indicated above related to the communicationscomponent 810, includes an indoor network radio transceiver 913 (e.g.,Wi-Fi transceiver). This function supports the indoor radio link, suchas IEEE 802.11, for the dual-mode GSM handset 900. The handset 900 canaccommodate at least satellite radio services through a handset that cancombine wireless voice and digital radio chipsets into a single handhelddevice.

Referring now to FIG. 10, there is illustrated a block diagram of acomputer 1000 operable to execute the functions and operations performedin the described example embodiments. For example, a network node (e.g.,network node 106, base station device 202, 204, e.g.,) may containcomponents as described in FIG. 10. The computer 1000 can providenetworking and communication capabilities between a wired or wirelesscommunication network and a server and/or communication device. In orderto provide additional context for various aspects thereof, FIG.1 and thefollowing discussion are intended to provide a brief, generaldescription of a suitable computing environment in which the variousaspects of the embodiments can be implemented to facilitate theestablishment of a transaction between an entity and a third party.While the description above is in the general context ofcomputer-executable instructions that can run on one or more computers,those skilled in the art will recognize that the various embodimentsalso can be implemented in combination with other program modules and/oras a combination of hardware and software.

Generally, program modules include routines, programs, components, datastructures, etc., that perform particular tasks or implement particularabstract data types. Moreover, those skilled in the art will appreciatethat the various methods can be practiced with other computer systemconfigurations, including single-processor or multiprocessor computersystems, minicomputers, mainframe computers, as well as personalcomputers, hand-held computing devices, microprocessor-based orprogrammable consumer electronics, and the like, each of which can beoperatively coupled to one or more associated devices.

The illustrated aspects of the various embodiments can also be practicedin distributed computing environments where certain tasks are performedby remote processing devices that are linked through a communicationsnetwork. In a distributed computing environment, program modules can belocated in both local and remote memory storage devices.

Computing devices typically include a variety of media, which caninclude computer-readable storage media or communications media, whichtwo terms are used herein differently from one another as follows.

Computer-readable storage media can be any available storage media thatcan be accessed by the computer and includes both volatile andnonvolatile media, removable and non-removable media. By way of example,and not limitation, computer-readable storage media can be implementedin connection with any method or technology for storage of informationsuch as computer-readable instructions, program modules, structureddata, or unstructured data. Computer-readable storage media can include,but are not limited to, RAM, ROM, EEPROM, flash memory or other memorytechnology, CD-ROM, digital versatile disk (DVD) or other optical diskstorage, magnetic cassettes, magnetic tape, magnetic disk storage orother magnetic storage devices, or other tangible and/or non-transitorymedia which can be used to store desired information. Computer-readablestorage media can be accessed by one or more local or remote computingdevices, e.g., via access requests, queries or other data retrievalprotocols, for a variety of operations with respect to the informationstored by the medium.

Communications media can embody computer-readable instructions, datastructures, program modules or other structured or unstructured data ina data signal such as a modulated data signal, e.g., a carrier wave orother transport mechanism, and includes any information delivery ortransport media. The term “modulated data signal” or signals refers to asignal that has one or more of its characteristics set or changed insuch a manner as to encode information in one or more signals. By way ofexample, and not limitation, communication media include wired media,such as a wired network or direct-wired connection, and wireless mediasuch as acoustic, RF, infrared and other wireless media.

With reference to FIG. 10, implementing various aspects described hereinwith regards to the end-user device can include a computer 1000, thecomputer 1000 including a processing unit 1004, a system memory 1006 anda system bus 1008. The system bus 1008 couples system componentsincluding, but not limited to, the system memory 1006 to the processingunit 1004. The processing unit 1004 can be any of various commerciallyavailable processors. Dual microprocessors and other multi-processorarchitectures can also be employed as the processing unit 1004.

The system bus 1008 can be any of several types of bus structure thatcan further interconnect to a memory bus (with or without a memorycontroller), a peripheral bus, and a local bus using any of a variety ofcommercially available bus architectures. The system memory 1006includes read-only memory (ROM) 1027 and random access memory (RAM)1012. A basic input/output system (BIOS) is stored in a non-volatilememory 1027 such as ROM, EPROM, EEPROM, which BIOS contains the basicroutines that help to transfer information between elements within thecomputer 1000, such as during start-up. The RAM 1012 can also include ahigh-speed RAM such as static RAM for caching data.

The computer 1000 further includes an internal hard disk drive (HDD)1014 (e.g., EIDE, SATA), which internal hard disk drive 1014 can also beconfigured for external use in a suitable chassis (not shown), amagnetic floppy disk drive (FDD) 1016, (e.g., to read from or write to aremovable diskette 1018) and an optical disk drive 1020, (e.g., readinga CD-ROM disk 1022 or, to read from or write to other high capacityoptical media such as the DVD). The hard disk drive 1014, magnetic diskdrive 1016 and optical disk drive 1020 can be connected to the systembus 1008 by a hard disk drive interface 1024, a magnetic disk driveinterface 1026 and an optical drive interface 1028, respectively. Theinterface 1024 for external drive implementations includes at least oneor both of Universal Serial Bus (USB) and IEEE 1394 interfacetechnologies. Other external drive connection technologies are withincontemplation of the subject embodiments.

The drives and their associated computer-readable media providenonvolatile storage of data, data structures, computer-executableinstructions, and so forth. For the computer 1000 the drives and mediaaccommodate the storage of any data in a suitable digital format.Although the description of computer-readable media above refers to aHDD, a removable magnetic diskette, and a removable optical media suchas a CD or DVD, it should be appreciated by those skilled in the artthat other types of media which are readable by a computer 1000, such aszip drives, magnetic cassettes, flash memory cards, cartridges, and thelike, can also be used in the example operating environment, andfurther, that any such media can contain computer-executableinstructions for performing the methods of the disclosed embodiments.

A number of program modules can be stored in the drives and RAM 1012,including an operating system 1030, one or more application programs1032, other program modules 1034 and program data 1036. All or portionsof the operating system, applications, modules, and/or data can also becached in the RAM 1012. It is to be appreciated that the variousembodiments can be implemented with various commercially availableoperating systems or combinations of operating systems.

A user can enter commands and information into the computer 1000 throughone or more wired/wireless input devices, e.g., a keyboard 1038 and apointing device, such as a mouse 1040. Other input devices (not shown)may include a microphone, an IR remote control, a joystick, a game pad,a stylus pen, touch screen, or the like. These and other input devicesare often connected to the processing unit 1004 through an input deviceinterface 1042 that is coupled to the system bus 1008, but can beconnected by other interfaces, such as a parallel port, an IEEE 1394serial port, a game port, a USB port, an IR interface, etc.

A monitor 1044 or other type of display device is also connected to thesystem bus 1008 through an interface, such as a video adapter 1046. Inaddition to the monitor 1044, a computer 1000 typically includes otherperipheral output devices (not shown), such as speakers, printers, etc.

The computer 1000 can operate in a networked environment using logicalconnections by wired and/or wireless communications to one or moreremote computers, such as a remote computer(s) 1048. The remotecomputer(s) 1048 can be a workstation, a server computer, a router, apersonal computer, portable computer, microprocessor-based entertainmentdevice, a peer device or other common network node, and typicallyincludes many or all of the elements described relative to the computer,although, for purposes of brevity, only a memory/storage device 1050 isillustrated. The logical connections depicted include wired/wirelessconnectivity to a local area network (LAN) 1052 and/or larger networks,e.g., a wide area network (WAN) 1054. Such LAN and WAN networkingenvironments are commonplace in offices and companies, and facilitateenterprise-wide computer networks, such as intranets, all of which mayconnect to a global communications network, e.g., the Internet.

When used in a LAN networking environment, the computer 1000 isconnected to the local network 1052 through a wired and/or wirelesscommunication network interface or adapter 1056. The adapter 1056 mayfacilitate wired or wireless communication to the LAN 1052, which mayalso include a wireless access point disposed thereon for communicatingwith the wireless adapter 1056.

When used in a WAN networking environment, the computer 1000 can includea modem 1058, or is connected to a communications server on the WAN1054, or has other means for establishing communications over the WAN1054, such as by way of the Internet. The modem 1058, which can beinternal or external and a wired or wireless device, is connected to thesystem bus 1008 through the input device interface 1042. In a networkedenvironment, program modules depicted relative to the computer, orportions thereof, can be stored in the remote memory/storage device1050. It will be appreciated that the network connections shown areexemplary and other means of establishing a communications link betweenthe computers can be used.

The computer is operable to communicate with any wireless devices orentities operatively disposed in wireless communication, e.g., aprinter, scanner, desktop and/or portable computer, portable dataassistant, communications satellite, any piece of equipment or locationassociated with a wirelessly detectable tag (e.g., a kiosk, news stand,restroom), and telephone. This includes at least Wi-Fi and Bluetooth™wireless technologies. Thus, the communication can be a predefinedstructure as with a conventional network or simply an ad hoccommunication between at least two devices.

Wi-Fi, or Wireless Fidelity, allows connection to the Internet from acouch at home, a bed in a hotel room, or a conference room at work,without wires. Wi-Fi is a wireless technology similar to that used in acell phone that enables such devices, e.g., computers, to send andreceive data indoors and out; anywhere within the range of a basestation. Wi-Fi networks use radio technologies called IEEE802.11 (a, b,g, n, etc.) to provide secure, reliable, fast wireless connectivity. AWi-Fi network can be used to connect computers to each other, to theInternet, and to wired networks (which use IEEE802.3 or Ethernet). Wi-Finetworks operate in the unlicensed 2.4 and 5 GHz radio bands, at an 11Mbps (802.11b) or 54 Mbps (802.11a) data rate, for example, or withproducts that contain both bands (dual band), so the networks canprovide real-world performance similar to the basic “10BaseT” wiredEthernet networks used in many offices.

As used in this application, the terms “system,” “component,”“interface,” and the like are generally intended to refer to acomputer-related entity or an entity related to an operational machinewith one or more specific functionalities. The entities disclosed hereincan be either hardware, a combination of hardware and software,software, or software in execution. For example, a component may be, butis not limited to being, a process running on a processor, a processor,an object, an executable, a thread of execution, a program, and/or acomputer. By way of illustration, both an application running on aserver and the server can be a component. One or more components mayreside within a process and/or thread of execution and a component maybe localized on one computer and/or distributed between two or morecomputers. These components also can execute from various computerreadable storage media having various data structures stored thereon.The components may communicate via local and/or remote processes such asin accordance with a signal having one or more data packets (e.g., datafrom one component interacting with another component in a local system,distributed system, and/or across a network such as the Internet withother systems via the signal). As another example, a component can be anapparatus with specific functionality provided by mechanical partsoperated by electric or electronic circuitry that is operated bysoftware or firmware application(s) executed by a processor, wherein theprocessor can be internal or external to the apparatus and executes atleast a part of the software or firmware application. As yet anotherexample, a component can be an apparatus that provides specificfunctionality through electronic components without mechanical parts,the electronic components can comprise a processor therein to executesoftware or firmware that confers at least in part the functionality ofthe electronic components. An interface can comprise input/output (I/O)components as well as associated processor, application, and/or APIcomponents.

Furthermore, the disclosed subject matter may be implemented as amethod, apparatus, or article of manufacture using standard programmingand/or engineering techniques to produce software, firmware, hardware,or any combination thereof to control a computer to implement thedisclosed subject matter. The term “article of manufacture” as usedherein is intended to encompass a computer program accessible from anycomputer-readable device, computer-readable carrier, orcomputer-readable media. For example, computer-readable media caninclude, but are not limited to, a magnetic storage device, e.g., harddisk; floppy disk; magnetic strip(s); an optical disk (e.g., compactdisk (CD), a digital video disc (DVD), a Blu-ray Disc™ (BD)); a smartcard; a flash memory device (e.g., card, stick, key drive); and/or avirtual device that emulates a storage device and/or any of the abovecomputer-readable media.

As it employed in the subject specification, the term “processor” canrefer to substantially any computing processing unit or devicecomprising, but not limited to comprising, single-core processors;single-processors with software multithread execution capability;multi-core processors; multi-core processors with software multithreadexecution capability; multi-core processors with hardware multithreadtechnology; parallel platforms; and parallel platforms with distributedshared memory. Additionally, a processor can refer to an integratedcircuit, an application specific integrated circuit (ASIC), a digitalsignal processor (DSP), a field programmable gate array (FPGA), aprogrammable logic controller (PLC), a complex programmable logic device(CPLD), a discrete gate or transistor logic, discrete hardwarecomponents, or any combination thereof designed to perform the functionsdescribed herein. Processors can exploit nano-scale architectures suchas, but not limited to, molecular and quantum-dot based transistors,switches and gates, in order to optimize space usage or enhanceperformance of user equipment. A processor also can be implemented as acombination of computing processing units.

In the subject specification, terms such as “store,” “data store,” “datastorage,” “database,” “repository,” “queue”, and substantially any otherinformation storage component relevant to operation and functionality ofa component, refer to “memory components,” or entities embodied in a“memory” or components comprising the memory. It will be appreciatedthat the memory components described herein can be either volatilememory or nonvolatile memory, or can comprise both volatile andnonvolatile memory. In addition, memory components or memory elementscan be removable or stationary. Moreover, memory can be internal orexternal to a device or component, or removable or stationary. Memorycan comprise various types of media that are readable by a computer,such as hard-disc drives, zip drives, magnetic cassettes, flash memorycards or other types of memory cards, cartridges, or the like.

By way of illustration, and not limitation, nonvolatile memory cancomprise read only memory (ROM), programmable ROM (PROM), electricallyprogrammable ROM (EPROM), electrically erasable ROM (EEPROM), or flashmemory. Volatile memory can comprise random access memory (RAM), whichacts as external cache memory. By way of illustration and notlimitation, RAM is available in many forms such as synchronous RAM(SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rateSDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), Synchlink DRAM (SLDRAM), anddirect Rambus RAM (DRRAM). Additionally, the disclosed memory componentsof systems or methods herein are intended to comprise, without beinglimited to comprising, these and any other suitable types of memory.

In particular and in regard to the various functions performed by theabove described components, devices, circuits, systems and the like, theterms (including a reference to a “means”) used to describe suchcomponents are intended to correspond, unless otherwise indicated, toany component which performs the specified function of the describedcomponent (e.g., a functional equivalent), even though not structurallyequivalent to the disclosed structure, which performs the function inthe herein illustrated example aspects of the embodiments. In thisregard, it will also be recognized that the embodiments comprise asystem as well as a computer-readable medium having computer-executableinstructions for performing the acts and/or events of the variousmethods.

Computing devices typically comprise a variety of media, which cancomprise computer-readable storage media and/or communications media,which two terms are used herein differently from one another as follows.Computer-readable storage media can be any available storage media thatcan be accessed by the computer and comprises both volatile andnonvolatile media, removable and non-removable media. By way of example,and not limitation, computer-readable storage media can be implementedin connection with any method or technology for storage of informationsuch as computer-readable instructions, program modules, structureddata, or unstructured data.

Computer-readable storage media can include, but are not limited to,random access memory (RAM), read only memory (ROM), electricallyerasable programmable read only memory (EEPROM), flash memory or othermemory technology, solid state drive (SSD) or other solid-state storagetechnology, compact disk read only memory (CD ROM), digital versatiledisk (DVD), Blu-ray disc or other optical disk storage, magneticcassettes, magnetic tape, magnetic disk storage or other magneticstorage devices or other tangible and/or non-transitory media which canbe used to store desired information.

In this regard, the terms “tangible” or “non-transitory” herein asapplied to storage, memory or computer-readable media, are to beunderstood to exclude only propagating transitory signals per se asmodifiers and do not relinquish rights to all standard storage, memoryor computer-readable media that are not only propagating transitorysignals per se. Computer-readable storage media can be accessed by oneor more local or remote computing devices, e.g., via access requests,queries or other data retrieval protocols, for a variety of operationswith respect to the information stored by the medium.

On the other hand, communications media typically embodycomputer-readable instructions, data structures, program modules orother structured or unstructured data in a data signal such as amodulated data signal, e.g., a carrier wave or other transportmechanism, and comprises any information delivery or transport media.The term “modulated data signal” or signals refers to a signal that hasone or more of its characteristics set or changed in such a manner as toencode information in one or more signals. By way of example, and notlimitation, communications media comprise wired media, such as a wirednetwork or direct-wired connection, and wireless media such as acoustic,RF, infrared and other wireless media

Further, terms like “user equipment,” “user device,” “mobile device,”“mobile,” station,” “access terminal,” “terminal,” “handset,” andsimilar terminology, generally refer to a wireless device utilized by asubscriber or user of a wireless communication network or service toreceive or convey data, control, voice, video, sound, gaming, orsubstantially any data-stream or signaling-stream. The foregoing termsare utilized interchangeably in the subject specification and relateddrawings. Likewise, the terms “access point,” “node B,” “base station,”“evolved Node B,” “cell,” “cell site,” and the like, can be utilizedinterchangeably in the subject application, and refer to a wirelessnetwork component or appliance that serves and receives data, control,voice, video, sound, gaming, or substantially any data-stream orsignaling-stream from a set of subscriber stations. Data and signalingstreams can be packetized or frame-based flows. It is noted that in thesubject specification and drawings, context or explicit distinctionprovides differentiation with respect to access points or base stationsthat serve and receive data from a mobile device in an outdoorenvironment, and access points or base stations that operate in aconfined, primarily indoor environment overlaid in an outdoor coveragearea. Data and signaling streams can be packetized or frame-based flows.

Furthermore, the terms “user,” “subscriber,” “customer,” “consumer,” andthe like are employed interchangeably throughout the subjectspecification, unless context warrants particular distinction(s) amongthe terms. It should be appreciated that such terms can refer to humanentities, associated devices, or automated components supported throughartificial intelligence (e.g., a capacity to make inference based oncomplex mathematical formalisms) which can provide simulated vision,sound recognition and so forth. In addition, the terms “wirelessnetwork” and “network” are used interchangeable in the subjectapplication, when context wherein the term is utilized warrantsdistinction for clarity purposes such distinction is made explicit.

Moreover, the word “exemplary” is used herein to mean serving as anexample, instance, or illustration. Any aspect or design describedherein as “exemplary” is not necessarily to be construed as preferred oradvantageous over other aspects or designs. Rather, use of the wordexemplary is intended to present concepts in a concrete fashion. As usedin this application, the term “or” is intended to mean an inclusive “or”rather than an exclusive “or”. That is, unless specified otherwise, orclear from context, “X employs A or B” is intended to mean any of thenatural inclusive permutations. That is, if X employs A; X employs B; orX employs both A and B, then “X employs A or B” is satisfied under anyof the foregoing instances. In addition, the articles “a” and “an” asused in this application and the appended claims should generally beconstrued to mean “one or more” unless specified otherwise or clear fromcontext to be directed to a singular form.

In addition, while a particular feature may have been disclosed withrespect to only one of several implementations, such feature may becombined with one or more other features of the other implementations asmay be desired and advantageous for any given or particular application.Furthermore, to the extent that the terms “includes” and “including” andvariants thereof are used in either the detailed description or theclaims, these terms are intended to be inclusive in a manner similar tothe term “comprising.”

The above descriptions of various embodiments of the subject disclosureand corresponding figures and what is described in the Abstract, aredescribed herein for illustrative purposes, and are not intended to beexhaustive or to limit the disclosed embodiments to the precise formsdisclosed. It is to be understood that one of ordinary skill in the artmay recognize that other embodiments having modifications, permutations,combinations, and additions can be implemented for performing the same,similar, alternative, or substitute functions of the disclosed subjectmatter, and are therefore considered within the scope of thisdisclosure. Therefore, the disclosed subject matter should not belimited to any single embodiment described herein, but rather should beconstrued in breadth and scope in accordance with the claims below.

What is claimed is:
 1. A user equipment, comprising: a processor; and amemory that stores executable instructions that, when executed by theprocessor, facilitate performance of operations, comprising: receiving alisten before talk trigger in a first mini-slot of a slot of a controlchannel; and performing a clear channel assessment on a channelindicated by the listen before talk trigger, comprising: in response tothe listen before talk trigger indicating that a listen before talkduration is less than a slot length of the control channel, sending aresult of the clear channel assessment in a second mini-slot of theslot, and in response to the listen before talk trigger indicating thatthe listen before talk duration is not less than the slot length of thecontrol channel, sending the result of the clear channel assessment in asubsequent slot of the control channel after the slot.
 2. The userequipment of claim 1, wherein performing the clear channel assessmentfurther comprises: in response to the listen before talk triggerindicating that the listen before talk duration is not less than theslot length of the control channel, performing the clear channelassessment beginning at a defined slot, other than the slot, indicatedby the listen before talk trigger.
 3. The user equipment of claim 1,wherein performing the clear channel assessment further comprises: inresponse to the listen before talk trigger indicating that the listenbefore talk duration is not less than the slot length of the controlchannel, performing the clear channel assessment beginning at a symboloffset indicated by the listen before talk trigger.
 4. The userequipment of claim 1, wherein performing the clear channel assessmentfurther comprises: in response to the listen before talk triggerindicating that the listen before talk duration is not less than theslot length of the control channel, determining a timing for performingthe clear channel assessment based on the listen before talk duration.5. The user equipment of claim 1, wherein the result of the clearchannel assessment comprises information associated with at least one ofa duration of the clear channel assessment, or a channel occupiedindication.
 6. The user equipment of claim 1, wherein the channel usesan unlicensed frequency band, and the control channel uses a licensedfrequency band.
 7. The user equipment of claim 1, wherein the channelcomprises a group of beams, and the clear channel assessment determinesthat a first beam of the channel is clear and that a second beam of thechannel is not clear.
 8. A method, comprising: facilitating, by networkequipment comprising a processor, receiving a listen before talk triggerin a first mini-slot of a slot of a first channel; and performing, bythe network equipment, a clear channel assessment using a second channelindicated by the listen before talk trigger, comprising: in response tothe listen before talk trigger indicating that a listen before talkduration is less than a slot length of the first channel, sending listenbefore talk feedback in a second mini-slot of the slot, wherein thelisten before talk feedback is based on a result of the clear channelassessment, and in response to the listen before talk trigger indicatingthat the listen before talk duration is not less than the slot length ofthe first channel, sending the listen before talk feedback in asubsequent slot of the first channel after the slot.
 9. The method ofclaim 8, wherein performing the clear channel assessment furthercomprises: in response to the listen before talk trigger indicating thatthe listen before talk duration is not less than the slot length of thefirst channel, performing the clear channel assessment beginning at adefined slot indicated by the listen before talk trigger.
 10. The methodof claim 8, wherein performing the clear channel assessment furthercomprises: in response to the listen before talk trigger indicating thatthe listen before talk duration is not less than the slot length of thefirst channel, performing the clear channel assessment beginning at asymbol offset indicated by the listen before talk trigger.
 11. Themethod of claim 8, wherein performing the clear channel assessmentfurther comprises: in response to the listen before talk triggerindicating that the listen before talk duration is not less than theslot length of the first channel, determining a timing for performingthe clear channel assessment based on the listen before talk duration.12. The method of claim 8, wherein the listen before talk feedbackcomprises at least one of a duration of the clear channel assessment, ora signal strength measurement.
 13. The method of claim 8, wherein thesecond channel uses an unlicensed spectrum, and the first channel uses alicensed spectrum.
 14. The method of claim 8, wherein the second channelcomprises a group of beams, and the clear channel assessment determinesthat a first beam of the second channel is clear and that a second beamof the second channel is not clear.
 15. A non-transitorymachine-readable medium, comprising executable instructions that, whenexecuted by a processor of a mobile device, facilitate performance ofoperations, comprising: receiving a listen before talk trigger in a slotof a licensed channel; and performing a clear channel assessment on anunlicensed channel indicated by the listen before talk trigger,comprising: in response to the listen before talk trigger beingdetermined to represent a listen before talk duration that is notgreater than a slot length of the licensed channel, sending a result ofthe clear channel assessment in a second mini-slot of the slotcomprising a first mini-slot in which the listen before talk trigger wasreceived, and in response to the listen before talk trigger beingdetermined to represent the listen before talk duration that is greaterthan the slot length of the licensed channel, sending the result of theclear channel assessment in a subsequent slot of the licensed channelafter the slot.
 16. The non-transitory machine-readable medium of claim15, wherein performing the clear channel assessment further comprises:in response to the listen before talk trigger being determined torepresent the listen before talk duration that is greater than the slotlength of the licensed channel, performing the clear channel assessmentbeginning at a defined slot indicated by the listen before talk trigger.17. The non-transitory machine-readable medium of claim 15, whereinperforming the clear channel assessment further comprises: in responseto the listen before talk trigger being determined to represent thelisten before talk duration that is greater than the slot length of thelicensed channel, performing the clear channel assessment beginning at asymbol offset indicated by the listen before talk trigger.
 18. Thenon-transitory machine-readable medium of claim 15, wherein performingthe clear channel assessment further comprises: in response to thelisten before talk trigger being determined to represent the listenbefore talk duration that is greater than the slot length of thelicensed channel, determining a timing for performing the clear channelassessment based on the listen before talk duration.
 19. Thenon-transitory machine-readable medium of claim 15, wherein the resultof the clear channel assessment comprises information associated with atleast one of a channel occupied indication, or a signal strengthmeasurement.
 20. The non-transitory machine-readable medium of claim 15,wherein the unlicensed channel comprises a group of beams, and the clearchannel assessment determines that a first beam of the unlicensedchannel is available and that a second beam of the unlicensed channel isunavailable.